Digital Watermarking Algorithm Implementation with MATLAB Code Package

In this article, we present a comprehensive implementation of digital watermarking algorithms using a MATLAB code package. The package includes: 1) DCT-based watermark embedding algorithm - implementing frequency-domain transformation using Discrete Cosine Transform with quantization index modulation 2) DWT-based watermark embedding algorithm - utilizing Discrete Wavelet Transform for multi-resolution watermark insertion in selected sub-bands 3) Watermark attack simulation module - containing common attack methods including noise addition, filtering, compression, and geometric transformations 4) Performance evaluation program - calculating key metrics such as PSNR, NC, and BER to assess watermark robustness and invisibility This implementation provides significant reference value through practical code examples that demonstrate complete workflow from watermark embedding to robustness testing, helping users better understand the application and performance evaluation of digital watermarking technologies.